John Booth felt that the offer from Toro Rosso was too good to turn down.

Toro Rosso offered him a role he could not refuse and former Manor Marussia principal John Booth is back in Formula One as the Red Bull-owned team's director of racing.

"I was just so exhausted at the end of last year I felt I couldn't even look at another racing car in my life," the 61-year-old Briton, kitted out in his new team uniform, told Reuters in the Russian Grand Prix paddock on Saturday.

"But after a winter away...the chance to come here, if I'd have turned it down I'd have regretted it for the rest of my life."

The Yorkshireman shares a trait in common with Toro Rosso's Austrian principal Franz Tost as someone who speaks his mind, however, unpalatable that may be to others. The two go back a long way.

"I'm really honoured to be here," said Booth, who will be working with the team on a consultancy basis, on his return to the F1 paddock for the first time since last year's closing Abu Dhabi Grand Prix.

"At the moment, I'm just getting used to people and learning the team. Just getting back into the 2016 regulations. There's no real agenda at the moment."

Booth is also active in the World Endurance Championship as principal of the Manor WEC team, no relation to the Manor F1 outfit that was previously Marussia, and his former chief executive Graeme Lowdon.

"I'm still involved with the WEC, I'll be at Spa next weekend," he said.

Tost said Booth had an important role to play at Italy-based Toro Rosso, effectively the Red Bull junior team who have Dutch teenager Max Verstappen and Spaniard Carlos Sainz as their drivers.

"Formula One is becoming ever more complex, with recent changes on the tyre front, car set-up, radio communications and so forth," said Tost.

"Having a competitive car and talented drivers, both of which we have, on its own is not enough. With his vast experience, I am sure John will help the team raise its game and become a more effective force over a race weekend."